1. Field of the Invention
The present invention relates to a system for aiding the preparation of an operation and maintenance plan for a power generation installation, and, in particular, relates to an operation and maintenance plan preparation aiding system for a power generation installation, in which a service center is provided. The service center manages operation and maintenance of a plurality of power generation units and prepares an operation and maintenance plan for respective power generation units by making use of plant data obtained from the respective power generation units through a communication network.
2. Conventional Art
Generally, many electric power generation companies, which operate an electric power generation business, own a plurality of power generation units. In order to manage the amount of power generated by these power generation units as a whole, comprise respective power generation systems are provided with a power supply command center (central supply) for every electric power generation company. In such power generation systems, the power supply command center assigns and adjusts the power generation amount for every power generation unit in response to power demand from consumers and each of the power generation units performs an operation while maintaining and adjusting the power generation amount assigned by the power supply command center. In such instances, the power supply command center prepares, in view of enhancing economy, an operation plan for the concerned power generation system so as to minimize fuel cost used in the power generation units, and to maximize power generation efficiency. As well, the command center prepares a plan, in view of placing priority on environmental protection, to keep the exhaust gas amount, such as nitrogen oxides and carbon dioxides exhausted from the power generation units, within an allowable range.
Now, the characteristics with regard to power efficiency and the exhaust gas amount which are used as references for the operation planning vary greatly depending on the kinds of fuel used and the power generation methods. With regard to fuels, in case of a thermal power generation, many kinds of fuels such as coal, petroleum and natural gas can be used, therefore, depending on the kind of fuels used, not only the power generation amount per unit fuel cost but also the amount and contents of the exhaust gas vary greatly. Further, with regard to power generation methods, the constitutions of machines and apparatuses of themselves such as power generation by a steam turbine, power generation by a gas turbine and a combined power generation combining thereof affect greatly their power generation efficiency. The power supply command center stores and preserves plant data (data representing the plant characteristics) obtained from these power generation units for every power generation unit, and uses the plant data when preparing operation plans for respective power generation units.
In the above referred to conventional power generation system, although the power supply command center stores and preserves the plant data for every power generation unit, these plant data were limited to the plant data at comparatively early stage of the respective power generation units, such as design values and those at the operation starting period of the power generation plants, however, the plant data varies gradually depending on passage of time as well as the contents of fuel being used, which also varies, therefore, it is difficult to prepare operation plans based on the current plant characteristics of the respective power generation units by making use only of the plant data.
Further, the above referred to conventional power generation system, since the machines and apparatuses such as a gas turbine constituting the power generating unit are always exposed to a high temperature, if load variation to the machines and apparatuses is frequently and repeatedly caused, deterioration of the machines and apparatuses due to thermal fatigue rapidly advances. For this reason, even if a fully economic operation which simply minimizes fuel cost for respective power generation units is employed, when the load variation to the machines and apparatuses is repeated, the lifetime of the machines and apparatuses is shortened, thus quickening the exchange time thereof, and therefore the total cost for the respective power generation units necessary for the plant operation, including the maintenance cost, is not necessarily minimized. Further, in the above referred to conventional power generation system, even if a plurality of power generation units having a high power generation efficiency are positively selected for the operation, when a provability of failure of the machines and apparatuses and the parts thereof constituting the power generation unit concerned is high, an unplanned outage is caused by a failure occurrence in the machines and apparatuses and the parts thereof which possibly causes an economic loss, therefore, even when an operation plan for a plurality of power generation units is prepared only based on fuel cost, the resultant cost was not necessarily minimized.